Protective Effect of Qidan Tongmia Tablet on Myocardium Microvascular Flow during Ischemia-Reperfusion of Dogs by Myocardial Contrast Echocardiography

Objective To investigate the effect of Qidan Tongmia tablet(QDTMT) on myocardial microvascular flow during ischemia-reperfusion using real-time myocardial contrast echocardiography (MCE). Methods 12 anesthesia dogs were randomly divided into two groups of control group and QDTMT treatment group: the animal was anesthetized and the left anterior descending coronary artery (LDA) of open-chest animal was isolated for measuring blood flow with an electromagnetic flow probe, then the animal was subjected to 90min of LAD occlusion followed by 180min reperfusion after 30min of administrating saline in control. The real-time imaging with MCE by FLASH model was performed during baseline, 90min of ischemia and 180min of reperfusion .During ischemia reperfusion,the parameters of time-intensity curve were measured in corresponding regional myocardium. Area under curve(AUC) was fit and washing-in by Echopac software package; presence or absence of perfusion defects area by the MCE was calculated for the risk area and for control area and the perfusion area was expressed as ratio of myocardium perfusion area (MPA) and left ventricular wall area(LVWA). The contents of NO and ET in coronary sinus were measured at the time points. Results No difference in AUC and the ratio of MPA/LVWA by MCE was observed between the control and QDTMT-treatment group during baseline, pre-ischemia and 90min occlusion ;myocardium microvascular flow during reperfusion in QDTMT-treatment group was significantly better than control group during 180min reperfusion ( 14.09±2.31 vs 11.47±1.55 P0.05); the myocardium perfusion area during 180 min reperfusion increased significantly in QDTMT-treatment group(92.10±2.2 % vs 87.49±4.12% in control, P0.05), LAD blood flow during pre-ischemia in QDTMT-treatment was higher than baseline and control respectively(P0.05). The contents of NO and ET in coronary sinus during 90 and 180min were significantly different respectively(68.98±10.01μmol/L (67.55±9.81) μmol/L and (114.73±11.89) μg/L,(139.97±12.36) μg/L in QDTMT-treatment group vs (56.38±8.27) μmol/L (53.55±6.03) μmol/L and (137.40±13.48) μg/L,(161.90±19.14) μg/L in control P0.05). Conclusion QDTMT could promote the myocardium microvascular flow restoration during ischemia reperfusion and regulate the contents of NO an ET in coronary sinus against ischemia reperfusion injury.